I have used Minia to assemble a contigs set from my paired end reads, as Minia instructed that it doesn't use pairing information for constructing assembly, then I continue to try SSPACE to exploit this pairing infomation from the SAME LIBRARY (which I have used to construct contigs set) for scaffolding. But after tried different parameters in SSPACE (k, a or parameters of lib.txt), it ALWAYS returns the scaffolded set exactly the SAME as initial contigs set. Did I miss something? Even if I didn't put the best parameters, I would be obtained a scaffold which might be somehow different from the initial contigs set, but here they are exactly the same.
Any suggestion is greatly welcomed, thanks a lot!

Satisfied in distance/logic within a given contig pair (pre-scaffold): 2175

Means only 2175 read pairs were found to connect contig pairs. So out of the ~600k paired reads, most were mapped onto the same contig and only 2175 mapped on two different contigs and satisfies the distance criteria. That's probably not enough for SSPACE to establish any scaffolds, depending on your thresholds for establishing links.

Your Minia assembly was good in the sense that it was able to fill the gaps between most of your paired reads (645344/657371 pairs satisfied the distance within one contig). If you want longer scaffolds, you'll probably need mate pair libraries.

edit**

It looks like you have ~6million single reads in your fastqs according to the summary report. Did you rename your fastq headers? Maybe SSPACE is not recognizing your pair-end reads correctly due to your header names?

It is really bizzare that after trying different parameters, I still get this same result, I think even if it got only 2175 linking reads for scaffolding, SSPACE still can merge some contigs, isn't it?
I didn't rename any fastq headers, I checked them by head and tail command and confirmed they remain corresponding paired end. Thanks!